1. Field of the Invention
This invention relates to apparatus for controlling the position of a plurality of machining shafts each including a machine tool fitted thereto so as to move these machining shafts to positions where desired machinings are subjected to a work piece.
2. Description of the Prior Art
In a machine tool having the ability of simultaneously subjecting a plurality of different types of machinings to one work piece, particularly, in a wood-working machine, it has been the common practice to determine the position of a plurality of machining shafts including suitable machine tools for various machinings fitted thereto by moving a movable block for supporting each machining shaft up to its given position by means of a servomotor. As a result, such kind of apparatus for controlling the position of a plurality of machining shafts comprises an operating panel for appointing the position of each machining shaft, a controller for generating an electric signal corresponding to the position thus appointed, and a plurality of servo-amplifiers each generating a driving current for driving each servomotor from the output signal delivered from the controller.
Such conventional apparatus must operate so as to appoint the position of each machining shaft everytime the desired kind of machining is changed. As a result, if use is made of a number of machining shafts, the above mentioned operations take a long time and there is a risk of these operations being erroneous.